1. Field of the Invention
The present invention relates to a spark plug for position-oriented installation in an internal combustion engine.
2. Description of Related Art
Spark plugs in diversified embodiments are known from the related art. Known spark plugs are installed, for example, by screwing the spark plug into a cylinder head. While the spark plug is being screwed in, the tightening torque rises, and after a specified tightening torque is reached, the screwing process is stopped. This brings about a random orientation of the ground electrode in the combustion chamber. In modern internal combustion engines it is required, however, that ignition take place at predetermined positions in the combustion chamber, so that, in this context, the position of the ground electrode is also important. Based on this idea, it was proposed that one should arrange a screw thread in the cylinder head to have a specified alignment, so that, after the installation of the spark plug, there exists a defined position of the ground electrode in the combustion chamber. This, however, requires increased costs in the production of the screw thread. It was also determined that a predefined tightening torque cannot always be obtained, in this instance. In the case of too low a tightening torque, the connection between the spark plug and the cylinder head may not be gastight, in particular. In addition, there is the danger that the screw connection between spark plug and cylinder head becomes loose or unscrewed. Too high a tightening torque, however, may lead to excessive stress on the spark plug or on the cylinder head. A spark plug is known from EP 1 039 601 B1, for which a seal made of sheet metal is proposed, which is deformed during the screwing-in process, and which offers the possibility of orienting the spark plug in the cylinder head. In this case, however, sealing problems are particularly able to occur.